Despite the flood story’s centrality in Genesis, it is barely mentioned later in the Bible. At its end, the LORD hastens to restore the world to its former state, as though nothing happened:

While the earth remaineth, seedtime and harvest, and cold and heat, and summer and winter, and day and night shall not cease.’ (Genesis 8:22)

עֹד כָּל יְמֵי הָאָרֶץ: זֶרַע וְקָצִיר, וְקֹר וָחֹם, וְקַיִץ וָחֹרֶף, וְיוֹם וָלַיְלָה – לֹא יִשְׁבֹּתוּ. (בראשית ח', כב)

Even when Noah’s drunkenness after the flood is recounted, he is described as a man of the soil – “And Noah the husbandman began, and planted a vineyard” (Genesis 9:20) – rather than a flood survivor, as we might expect. “Man of the soil” recalls his naming by his father Lamech before the flood:

And he called his name Noah, saying: ‘This same shall comfort us in our work and in the toil of our hands, which cometh from the ground which the LORD hath cursed.’ (Genesis 5:29)

וַיִּקְרָא אֶת שְׁמוֹ נֹחַ, לֵאמֹר: זֶה יְנַחֲמֵנוּ מִמַּעֲשֵׂנוּ וּמֵעִצְּבוֹן יָדֵינוּ – מִן הָאֲדָמָה אֲשֶׁר אֵרְרָהּ ה'. (בראשית ה', כט)

The flood is thus ignored and passed over as though it never occurred.

Indeed, although the LORD destroyed all humanity and left only righteous Noah, human nature did not change. Before the flood, the LORD saw “that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually” (Genesis 6:5), and therefore said: “I will blot out man whom I have created from the face of the earth; both man, and beast, and creeping thing, and fowl of the air; for it repenteth Me that I have made them” (Genesis 6:7). After the flood: “and the LORD said in His heart: ‘I will not again curse the ground any more for man’s sake; for the imagination of man’s heart is evil from his youth; neither will I again smite any more every thing living, as I have done’” (Genesis 8:21).

The only change following the flood seems to have been the LORD’s attitude toward His creatures: from a strict, punitive approach to a more tolerant, accommodating one. Earth’s corruption and the ensuing flood taught that humans naturally incline toward evil and cannot meet high expectations without guidance and explicit law. In this respect, the flood’s lesson was the LORD’s alone.

This finds expression on two levels. First, the LORD unilaterally undertook never again to flood the earth, whatever human behavior might be. The rainbow symbolizes the covenant’s unilateral character. The bow belongs to the LORD; He places it in the cloud, and it reminds Him (see Nahmanides on Genesis 9:12).

Second, the conception of humanity and expectations of it also changed. After creation, the LORD believed humanity fundamentally good and capable of proper action without explicit commands or external intervention; there was therefore no need to forbid murder or require enforcing its prohibition. After ten generations, from Adam to Noah, it became clear that humans have impulses drawing them toward evil and need guidance and assistance. After the flood, what should have been self-evident therefore had to be defined in explicit law, and humanity commanded to enforce it:

Whoso sheddeth man’s blood, by man shall his blood be shed; for in the image of God made He man. (Genesis 9:6)

שֹׁפֵךְ דַּם הָאָדָם – בָּאָדָם דָּמוֹ יִשָּׁפֵךְ, כִּי בְּצֶלֶם אֱלֹהִים עָשָׂה אֶת הָאָדָם. (בראשית ט', ו)

The flood story thus represents a double turning point: a new divine “understanding” of human limitations, and the establishment of a legal and moral foundation intended to guide humanity, prevent moral deterioration, and build a more stable human order for the future.